A variety of magnets are utilized in an increasing number of applications including, for example, in the stator and rotor of electric motors and generators. In this regard, with the growing interest in electric vehicles and in renewable energy applications that utilize electric motors and generators, the demand for magnets is correspondingly growing.
The magnets utilized in the stator and rotor of electric motors and generators may include permanent magnets formed of various materials, such as rare earth neodymium iron boron in order to increase the flux density in the air gap. The magnets may also be arranged in a Halbach array, arranged to have a dual flux path, or configured to have an iron backing or a yoke so as to further increase the flux density in the air gap.
In many applications, however, magnets are desired to provide even further increased levels of flux density without increasing the size and weight, or perhaps while reducing the size and weight, of the resulting magnet structure. By increasing the flux density while maintaining or decreasing the size and weight of the magnet structure, the performance and efficiency of the magnet structure may be increased, thereby correspondingly improving the performance and efficiency of the electric motor or generator. In instances in which the magnet structure is utilized in a vehicular application, such as an electric vehicle or an airborne vehicle, the increased performance and efficiency may provide reduced fuel consumption and/or increased range and reliability. Similarly, in renewable energy applications that utilize electric motors or generators, a magnet structure offering improved performance and efficiency with no corresponding increase in weight may correspondingly improve the performance and potentially decrease the cost of the electric motors and generators utilized in the renewable energy applications.
Accordingly, it would be desirable to provide an improved magnet structure capable of providing increased flux density in the air gap of an electric motor, generator or the like without a corresponding increase in the size and weight of the magnet structure.